The present invention relates to a device for reducing the mount of light output by a flash or strobe tube without affecting the light output from an attached modeling light.
A typical photo strobe unit consists of a power pack unit and a strobe or flash head. The flash head has two separate and different lighting sources, a modeling light and a flash tube. The modeling light, typically is a tungsten lamp, provides light used to simulate the light output from the flash tube, to light the subject for focusing, and to be the general light used for setup and styling or arrangement of the subject to be photographed. The flash tube, when fired, provides the actual light that exposes the film or digital image sensor.
The amount of light output from the flash tube is controlled by various settings on the power pack unit. Since a photo situation may require multiple lights at different output amounts or at different distances, typical power pack units have multiple settings ranging from low the high output. However, there are situations where the light required to be close to the subject for an effect, style, or certain xe2x80x9clookxe2x80x9d commonly requires great reduction in the flash output well below the lowest output setting of the power unit. Thus, there is a recognized need for methods and devices to further reduce or control the output of photo strobe units.
Known methods for reducing flash head output or-light to film/sensor include the following:
Bleeder heads. The power unit typically contains xe2x80x9cbanksxe2x80x9d of discharge capacitors that supply power to the flash tube. The different power settings of the power unit control the number or amount of capacitors to be discharged. Also, a typical power unit will have more than one receptacle or output plug for each xe2x80x9cbankxe2x80x9d of capacitors. By varying the power settings and use of receptacles, various different power outputs may be achieved. For example, a xe2x80x9cbankxe2x80x9d or power unit having four output receptacles will provide 100% of the preselected power output to the flash tube when only one flash head is connected. When two flash heads are connected to the same xe2x80x9cbankxe2x80x9d, the output would be 50% power to each flash head. By connecting four flash heads to the same xe2x80x9cbankxe2x80x9d the output to each flash head would be 25% power to each flash head. To use one flash head at 25% power requires three additional flash heads connected in order to xe2x80x9cbleedxe2x80x9d out the other power of that xe2x80x9cbank xe2x80x9d only. This method requires the xe2x80x9cbleeder headsxe2x80x9d to be isolated in order to prevent their undesirable light output from affecting the desired subject lighting. With this method a situation requiring three lights at 25% power would require a total of twelve flash heads in which nine flash heads used as xe2x80x9cbleederxe2x80x9d heads and must be isolated so not to adversely affect the subject lighting. While this method does work to reduce light output, it is clearly not the best solution, especially if non-integral amounts of light are desired.
Neutral Density or ND filters over flash head. This method requires neutral density filter to be placed over the flash head. This is not always practicable since the ND filter needs to be placed away from the modeling light due to the high temperature of the light. Because of this need for distance from the flash tube, this method reduces light output from both the flash tube and modeling light. As the modeling light output is reduced, the ability to see the direction, style, and various qualities of the anticipated flash tube illumination is diminished.
ND filter over lens. A neutral density filter may be placed over the camera lens. This method makes focusing and general viewing difficult and does not work if all light outputs are not to be reduced by the same amount of reduction given by the ND filter. Further, the removing and replacing of the filter every time, in order to check focus, light and position, makes this method less desirable due to the general hassle and chance of forgetting to reinstall filter before making an exposure.
Increase distance from light to subject. This distance between the light and the subject may be increased. By increasing distance of the subject to the light there is a general loss of control, general viewing and accurate focus conditions.
Thus it can be seen that there is an existing and continuing need for devices that allow the easy reduction of light output from a flash tube, while leaving the modeling light output unaffected.
The present invention relates to a filter device for reducing the light output of a flash tube, while leaving the light output of a modeling light tube unaffected, in a dual lamp photo strobe unit. Therefore:
It is an object of the present invention to provide a filter device that fits over a flash tube of a dual light photo strobe unit, said device allowing a modeling light tube to project from the device thereby leaving the light output of the modeling light tube unaffected.
It is another object of the present invention wherein said filter is comprised of a mesh like material that allows a reduction in the amount of light provided by the flash tube.
It is a further object of the present invention wherein said mesh-like material is a metallic material that does not melt at temperatures created by flash tube use.
It is yet another object of the present invention to provide a series of differently sized filters that may be nestled within each other in order to provide a controllable reduction in the amount of light provided by the flash tube, while leaving the output of the modeling light unaffected.
It is still yet a further object of the present invention to provide a variety of different shaped filters that will conform with the different shapes and models of photo strobe units.